117,561 research outputs found
Phytochemistry of Three Ecuadorian Lamiaceae: <i>Lepechinia heteromorpha</i> (Briq.) Epling, <i>Lepechinia radula</i> (Benth.) Epling and <i>Lepechinia paniculata</i> (Kunth) Epling
No full textIn this research, the leaves of Lepechinia heteromorpha (Briq.) Epling, Lepechinia radula (Benth.) Epling and Lepechinia paniculata (Kunth) Epling have been collected in order to perform a phytochemical study. The first species was distilled to obtain a novel essential oil (EO), while the others were submitted to ethyl acetate extraction and secondary metabolite isolation. The chemical composition of the EO from L. heteromorpha has been investigated by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography with Retention Indices (GC(RI)), identifying 25 constituents. A major compound, (−)-ledol (21.2%), and a minor compound, (−)-caryophyllene oxide (1.0%), were isolated from the EO and their structures confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy. Other major constituents of the EO were viridiflorene (27.3%), (E,E)-α-farnesene (1.4%), spirolepechinene and (E)-β-caryophyllene (7.1% each), allo-aromadendrene (6.1%), camphor (1.7%), limonene (1.3%) and β-phellandrene (4.6%). The enantiomeric composition of the EO monoterpene fraction was also studied, determining the enantiomeric excess and distribution of α-pinene, limonene, β-phellandrene and camphor. The ethyl acetate extract of L. radula and L. paniculata were fractionated by column chromatography. Spathulenol, angustanoic acid E and 5-hydroxy-4′,7-dimethoxy flavone were isolated from L. radula extract; ledol, guaiol and (−)-carnosol were found in L. paniculata.</i
Composición fitoquímica de la Satureja brevicalyx Epling
No full textIntroduction: Epling brevicalyx savory grows in the southern Andes of Peru (Ayacucho, Apurimac, Cuzco and Puno), between altitudes of 3300-3800 m, within the chemical composition of the essential oil of Satureja brevicalyx can find several constituents as mentonas, pulegonas, linalool. Traditionally it has been used as a digestive, against gastritis, flatulence and antispasmodic.Objective: To identify the chemical composition of the ethanol extract, hexane / ethanol and the aqueous brevicalyx Satureja Epling for secondary metabolites that are of interest in biological therapeutics.M e t h o d s : T h e l e a v e s w e r e e x u d e d a n d dehydrated at room temperature, obtaining a greenish dry powder which underwent successive extractions with solvents of increasing polarity. To the obtained extracts phytochemicals identification assays.R e s u l t s : T h e p h y t o c h e m i c a l s c r e e n i n g , conducted at the ethanolic extracts, hexane / aqueous ethanol and the leaves, showed the existence of several families of secondary metabolites of biological and pharmacological interest, among which stand out for their significant presence of quinones, flavonoids, alkaloids, phenols, tannins.Conclusions: According to the presence of secondary metabolites in the leaves of Satureja brevicalyx Epling and pharmacological effects reported for the essential oil of the species, it would be important to conduct further studies to serve as evidence to support its traditional use taking into account the efficacy and safety of this plant.
Satureja brevicalyx Epling crece en la parte sur andina del Perú (Ayacucho, Apurimac, Cuzco y Puno), entre las altitudes de 3300-3800 msnm, dentro de la composición química del aceite e s e n c i a l d e S a t u r e j a b r e v i c a l y x p o d e m o s encontrar varios constituyentes como mentonas, pulegonas, linalol. Tradicionalmente se ha usado como digestivo, contra la gastritis, flatulencia y antiespasmódica.OBJETIVO:Identificar la composición química del extracto etanólico,Hexano/etanol y acuoso de la Satureja brevicalyx Epling para conocer los metabolitos secundarios que sean de interés biológico en la terapeútica. MÉTODOS:Las hojas fueron exudadas y deshidratadas a temperatura ambiente, obteniéndose un polvo seco de color verdoso al cual se sometieron a extracciones sucessivas com solventes de polaridad creciente. A los extractos obtenidos se realizaron ensayos fitoquímicos de identificación. RESULTADOS:El tamizaje fitoquímico ,efectuado a los extractos etanólico, hexano/etanol y acuoso de la hojas,demostró la existencia de varias familias de meta bolitos secundarios de interés biológico y farmacológico, entre los que se destacan, por su significativa presencia las, quinonas, flavonoides, alcaloides ,fenoles , taninos. CONCLUSIONES : De acuerdo a la presencia de los metabolitos secundarios presentes en las hojas de la Satureja brevicalyx Epling , así como los efec tos farmacológicos reportados para el aceite esencial de la especie, sería importante efectuar nuevos estudios que sirvan como evidencias para avalar su empleo tradicional teniendo en cuenta la eficacia y seguridad de esta planta
Phytochemicals of minthostachys diffusa epling and their health-promoting bioactivities
No full textThe genus Minthostachys belonging to the Lamiaceae family, and is an important South American mint genus used commonly in folk medicine as an aroma in cooking. The phytochemical-rich samples of the aerial parts of Minthostachys diffusa Epling. were tested for pharmacological and health-promoting bioactivities using in vitro chemical and enzymatic assays. A range of radical scavenging activities of the samples against biological radicals such as nitric oxide and superoxide anion and against synthetic 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, the ferric reducing antioxidant power and the lipid peroxidation inhibition were determined and ranked using the 'relative antioxidant capacity index' (RACI). The ethyl acetate fraction showed the highest RACI of +1.12. Analysis of the various fractions' inhibitory ability against enzymes involved in diabetes (α-amylase and α-glucosidase), and against enzymes associated with Parkinson's or Alzheimer's diseases (acetylcholinesterase and butyrylcholinesterase) also suggested that the ethyl acetate fraction was the most active. Liquid chromatography-tandem mass spectrometry analysis of the ethyl acetate fraction showed more than 30 polyphenolic compounds, including triterpenes. The inhibitory cholinesterase effects of the triterpenes identified from M. diffusa were further analysed by in silico docking of these compounds into 3D-structures of acetylcholinesterase and butyrylcholinesterase. This is the first study on pharmacological activities and phytochemical profiling of the aerial parts of M. diffusa, showing that this plant, normally used as food in South America, is also rich in health-promoting phytochemicals
Chemical composition and antimicrobial activity of Lepechinia radula Benth Epling from Ecuador: the essential oil.
No full textThe essential oil (EO) from the aerial parts of Lepechinia radula Benth Epling (Lamiaceae) from Ecuador was obtained by hydrodistillation. The chemical composition was determined by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/flame ionization detection (GC/FID) analysis. Thirty-four compounds accounting to 93.4% of the total oil were identified. The main constituents of the essential oil were ?-3-carene (19.9%), ?-pinene (17.0%), (E)-?-caryophyllene (9.7%) and (E-E)-?-farnesene (9.4%). In order to determine antimicrobial activity of the essential oils, broth microdilution method was used. The essential oil of L. radula possessed strong antifungal activity against Trichophyton rubrum (ATCC� 28188) and Trichophyton mentagrophytes (ATCC� 28185)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing
No full textHear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing.
Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal.
Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp
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